Update app.py

app.py

@@ -67,6 +67,8 @@ def get_audio_features(token, track_ids):
 
 def get_tracks_and_features(token, url):
     headers = {'Authorization': f'Bearer {token}'}
+    track_ids = None
+    
     if "track" in url:
         track_id = url.split("/")[-1].split("?")[0]
         track_ids = [track_id]
@@ -76,7 +78,8 @@ def get_tracks_and_features(token, url):
         response = make_request_with_retry(tracks_url, headers)
         if response:
             track_ids = [item['track']['id'] for item in response.json().get('items', []) if item['track']]
-    else:
+    
+    if not track_ids:
         return None, None
 
     audio_features = get_audio_features(token, track_ids)